A few days ago I happened to see on TV the end of a piece on virgin olive oil which one of our major commercial television networks was airing. The presenter was a well-dressed lady and she praised the benefits of virgin olive oil and had a display of different bottles from what appeared to be different manufacturers.

I was more than happy to agree with what was being said until she said that it was perfectly safe to cook with olive oil. I raised my eyebrows and pricked up my ears. That didn’t sound quite right. Having studied Biochemistry at university, I had previously delved into aspects of olive oil and its composition and knew it to be composed mainly of Oleic Acid (OA), a monounsaturated oil, which is more commonly known as Omega-9 oil.

As humans, there are two oils (known as fatty acids (FA) in the Biochemist’s world) that are classified as essential fatty acids. This means we can’t make them in our bodies; we have to get them through our food. These are Linoleic Acid (LA or Omega-6) and Alpha-Linolenic Acid (ALA or Omega-3). Both of these FAs are polyunsaturated, which means that they have more than one unsaturated bond in their molecular structure. LA has two and ALA has three. The higher the number of unsaturated (or double) bonds in the structure, the less stable the compound is at higher temperatures.

Oleic Acid (Omega-9) is also considered essential to have in our food, because we don’t make it in sufficient quantities to be highly beneficial. This is a monounsaturated FA as it only has one unsaturated bond in its structure. This makes it more stable at higher temperatures than Omega-6 or Omega-3 oils, but is still has the ability to change into a less desirable structure when it is heated.

Olive oil has a melting point of -6oC, which means it stays fluid all the way down to 6 degrees below freezing after which point it freezes. Most domestic freezers are set at -4oC, so your olive oil will not freeze at this temperature, unless it has impurities in it.

The boiling point of olive oil is 700oC which is extremely high relative to the normal domestic kitchen burner, which reaches temperatures closer to 250-300oC. This was what the lady alluded to when she stated that the domestic cooker temperatures won’t reach a temperature high enough to destroy the good qualities of the oil.

Unfortunately, she was being misleading when she said this.

We will probably never heat oil to its boiling point, but we can certainly heat it to its smoke point. This is an entirely different scenario and its effect on certain oils can be very detrimental.

Heating oil to the point of when is begins to smoke produces toxic fumes and harmful free radicals. It also causes the chemical structure of the unsaturated fats to change to trans fats, which then act as if they were a saturated fat. These can be more harmful due to their rigid molecular structure, rather than having the beneficial kinked structure of the mono and polyunsaturates.

 

The smoke point of extra virgin olive oil, which is the best of this type of monounsaturated oil, is 160oC, composed of 73% monounsaturated FA, Omega-9

 

Unrefined flaxseed, safflower, sunflower oil all have SP 107oC and are 1:4 (Omega-6: Omega-3 ratio), 133:1, and 40:1, respectively.

Butter 177oC, 9:1 mostly saturated and monounsaturated

Coconut Oil SP 177oC (Lauric Acid) is a 86% healthy saturated fat, antibacterial, antiviral, antioxidant properties – 66% medium chain triglycerides (MCTs)

Unrefined Sesame Oil SP 177oC, 138:1

Sesame Oil SP 210oC, 42:1

Virgin Olive Oil SP 216oC, 13:1, 74% monounsaturated (71.3% Omega-9)

Peanut Oil SP 227oC, 32:1

Sunflower Oil SP 227oC, 40:1

Rice Bran Oil SP 254oC, 21:1 good source of Vit E & antioxidants.

Avocado Oil SP 271oC, 12:1 70% monounsaturated (68% Omega-9 fatty acid), high in Vit E.

 

Heating unsaturated oils is not desirable because their beneficial structure can be destroyed.

Use other oils for cooking because their structure is much more stable at higher temperatures.

She then went on to state that coconut oil was not a good oil to use as there were no studies done to show it was beneficial. It is however a medium chain triglyceride which has many beneficial properties which no study can disprove. It has antibacterial and antiviral properties and it is also an antioxidant (check this…). This can only be good for the upper parts of the human digestive tract and in the mouth. That’s why it is used extensively for oil pulling (a process to draw out toxins and microorganisms from the mouth at the very start of your day).

The hosts then agreed that it has a strong flavour and made all their food taste like coconut. Personally, I have used coconut oil exclusively in my cooking and can’t even notice its flavour. I have also found that some oils are stronger than others, so I use the extra virgin organic varieties.

I have other benefits gleaned from using coconut oil, which helped me recover from epilepsy.

More on that another time.